Magnet control structure



c ma My 3, 1960 H. A. HOWELL 2,935,583

MAGNET CONTROL STRUCTURE Filed Jan. 17, 1958 2 Sheets-Sheet 1 May 3 1960 H. A. HowELl. y 2,935,583

MAGNET coNTRoL STRUCTURE 'Filed Jan. 17, 195e 2 sheets-sheet z United States Patent O MAGNET CONTROL STRUCTURE Hugh A. Howell, Berwyn, Ill., assignor to Oak Mfg. Co., Cook County, Ill., a corporation of Illinois Application January 17, 1958, Serial No. 709,585 7 Claims. (Cl. 200-87) This invention relates to a magnet control structure and more particularly to a construction for effecting a magnetic control of a magnetizable member through a wall or partition.

It is old to provide a control magnet on one side of a non-magnetic partition and an armature load upon the other side of the partition for obtaining a remote control action. Thus the armature-load may be attached to or form part of an electric switch, valve or other device whose position must be changed by the control magnet. Such a construction may be desirable or essential where ambient conditions at the partition or wall sides are dissimilar or incompatible.

There are two general types of such magnetic devices. In one type, which may be'designated as a power type, there may be an electric field structure which is outside of a non-magnetic partition operating on a motor rotor within the magnetic partition. In a different type, which may be considered as a control type, the control member on one side of the partition and load upon the other side of the partition are adapted to move into or out of one or more distinct positions. The present invention relates to the latter type where the load or controlled part has distinct positions andthe objective is to transmit a controlling force rather than power.

It is well known that the overall permeability of a ferromagnetic circuit is drastically reduced by the presence of even a minute air gap (or non-magnetic gap). Where a non-magnetic partition is required for separating a controlling magriet from its load, the effective thickness of such a partition, as a practical matter, will have to be substantialand thus will introduce a large non-magnetic gap or gaps in the magnetic circuit. Because of this, remote magnet control constructions have not been used to any great extent.

This invention makes possible a construction which permits a partition to separate a permanent magnet or the pole pieces thereof on the one hand from other permanent magnets or armatures as a load while obtaining the same order of magnetic etliciency as in a conventional ferro-magnetic construction where no partition is present.

From the very nature of a magnet control, it is clear that a partition must generally be of non-magnetic mate-l rial. However, the essence of the present invention lies in the provision of a partition of generally non-magnetic material but having local portion or portions of ferromagnetic material for completing the magnetic circuit under certain operating conditions. In one simple form of the invention, a at partition or wall may be provided with ferro-magnetic inserts at regions Where magnetic action is to occur. Upon one side of the partition there may be a control magnet, either permanent or electro magnet, having suitable pole faces. Upon the other or controlled or load side of the partition there may be disposed device or devices which are magnetically responsive to be operated or controlled. The device to be controlled has its magnetically responsive part in proximity to one or more ferro-magnetic inserts in the partition.

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Thus, the partition may be at with a control member.

movable on or toward one face of the partition. The partition with its magnetic inserts may also be cylindrical with a control member upon one side of the cylinder'and the load upon the other side of the cylinder. Other partition shapes are possible. In order that the invention may be fully understood and appreciated it will now bedisclosed in connection with the drawings wherein- Figure 1 is a plan view from the load side of one;

embodiment of the invention.

Figure 2 is a section along line 2-2 of Fig. 1.

Figure 2A is an exploded View of the control parts of the structure of Fig. l.

Figure 3 is a plan view from the control side of the structure shown in Fig. l.

Figure 4 is a view partly in section of a modified form of the invention.

Figure 5 is a view along line 5-5 of Fig. 4.

Figure 6 is a view partly in section of a further modiication.

Figure 7 is a view along line 7-7 of Fig. 6.

Figure 8 is a sectional view of a still further modifica-v tion.

Figure 9 is a sectional view of an additional moditication.

Referring tirst to Figs. 1 to 3 inclusive, there is provided supporting wall or partition 10 of non-magnetic material. Wall 10 may be of metal, plastic, or any other material which is substantially non-magnetic. The char-r` control function from one side of the partition to the? other side of the wall.

Partition 10 carries insulating disk 12 upon which may be mounted a number of movable spring arms 13. Each arm 13 may be anchored at 14 to disk 12 by any suitable means such as a screw or rivet. As illustrated in Fig. 2, each screw 14 passes through insulating disk 12 and into partition 16. If partition 10 is of metal, it may be desirable to insulate each spring arm 13, which will usually be ofmetal, from its mounting. Spring arm 13 may consist of soft iron or soft steel or may even consist of spring steel or of non-magnetic material as Phosphor bronze or of non-metallic material as rubber. For the purposes of this invention, it is not essential that'arm 13v be of magnetic material although the arm may function as a combined spring and armature.

Arm 13 carries at its free end movable contact 16 which cooperates with xed contact 17 supported ou insulating strip 18 carried by-partition 10. As illustrated here, the various arms 13 are radially disposed yfrom the center of disk 12 with the free ends of the arms lying in an annular region defined by insulating strip 18. The annular arrangement of contacts and mounting thereof may be varied and generally may be conventional.

Carried by each arm 13 is armature 20 of soft iron o'r soft steel. Armature 20 may be considered as a magepesses netically responsive member which cooperates with, in this instance, a pair of ferro-magnetic inserts 21 and 22 in partition it?. The exact shape of the inserts is unimportant and whether the inserts are ush with either surface of partition 2lb is not important. Inserts 21 and 22 are suciently large and are so shaped and located .that armature 20 can bridge and contact the insert faces.

Ferro-magnetic inserts 21 and 22 are permanently dis posed in partition 10 and are mounted in such fashion that tight and satisfactory retention will be provided. Thus, as an example, inserts 21 and 22 may of soft iron while partition i may be of non-magnetic stainless steel, a non-magnetic manganese iron alloy or any other material. For example, partition lil may be of plastic or of glass, of copper, brass, or aluminum. If partition is of metal, it might be desirable to weld ferro-magnetic inserts 21 and 22 into position. The inserts may also be brazed or swedged into position. Where large variations in temperature are to occur, it may be necessary to select materials whose differences in expansion will not be harmful.

Against face 10a of wall 10, there is provided a permanent magnet assembly generally indicated by 26. As illustrated in Fig. 2, stub shaft or pin 27 preferably of non-magnetic material is anchored in or upon partition 10. Rotatably supported on pin 27 is an assembly consisting of permanent magnet 2S and pole pieces 29 and 30. As illustrated in Fig. 2A, permanent magnet 28 is annular while pole pieces 29 and 30 have arms 31 and 32 with pole faces 33 and 34 respectively.

Permanent magnet 28 may be any one of a number of different materials-Amico V, or may be of the new ceramic materials now available. Permanent magnet 28 is polarized so that the opposite annular faces a and b constitute the pole faces of the magnet. The assembly may be secured on pin 27 by locking pin 36 carried by pole piece 30, the locking pin working in a suitable slot on pin 27. Pole pieces 29 and 30 are so desined that pole faces 33 and 34 can cooperate with ferro-magnetic inserts 22 and 21 respectively.

It -is clear that when control assembly 26 is moved so that pole faces 33 and 34 bear upon the faces of a pair of inserts 21 and 22 that armature 20 will be attracted to operate the switch. It is clear that instead of closing switch contacts they may be so arranged that contacts are opened or one pair may be opened and another may be closed. Also instead of spring arm 13 carrying contacts, the spring arm may operate other mechanism or devices. The switch arrangement is susceptible to wide variations.

In the construction described, the magnetic circuit may be traced as follows. From one magnet face along one pole piece arm to a ferro-magnetic insert in partition 1), thence through armature to the companion ferromagnetic insert and along the remaining pole piece arm back to the other magnet face.

The magnetic circuit may be re-arranged so that only one ferro-magnetic insert is necessary. Thus one of the pole pieces, such as 29, may be omitted in which case a corresponding pole piece should be provided on the load face 10b of partition 10. In that case, it may be desirable to have pin 2'7 of ferro-magnetic material or have a central ferro-magnetic insert for the partition.

VIt is also possible to have arm 13 carry a permanent magnet instead of armature 20 and adjust the spring bias of arm 13 so that pole faces 33 and 34 are required to be present at inserts 21 and 22 for proper action. In such case, care will have to be exercised to observe proper polarity of the magnet.

The exact details of the construction of the ferro-magnetic circuit and the nature of the load may be varied within wide limits. lt may even be possible to have one or both inserts of permanent magnet material and adjust the tension of arm 13 so that a ferro-magnetic member such as pole pieces 29 and 30 must rest upon the inserts CFI and close the magnetic circuit for proper operation. In such case, permanent magnet 28 may be omitted.

As illustrated in Figs. 1 to 3 inclusive, the ferro-magnetic inserts are arranged so that one pair of inserts are disposed in radial alignment. This is not essential. Where a pair of inserts are used, it is possible to dispose each one of a pair in any other desired relation such as, for example, along the arc of a circle providing that the two pole faces can cooperate with one pair of inserts. As will be apparent later, in connection with other modifications, it is not essential that the inserts be provided iu pairs. As illustrated in Fig. 8 to be described later, three inserts may cooperate in such fashion as to be the equivalent to two pairs of inserts.

it is also understood that the control assembly need not necessarily move along the partition face. It is pos-A sible to move the control assembly toward and away from a pair of inserts along a path normal to the partition face.

Electro-magnets may be used in place of or supplementary to permanent magnets.

The invention so far described has been embodied in a construction utilizing a dat wall or partition. As has been previously indicated, other partition shapes are possible and in the modication illustrated in Figs. 4 and 5, there is utilized a generally cylindrical partition. Referring to these figures, support member 40 has a separating wall or partition 41 of generally cylindrical shape. Member 4i) has fiat supporting wall 42 carrying partition 41 and also carrying supporting ange 43. Supporting flange 43 may carry a number of switch units comprising stationary contact arm 45 and movable contact arm 46. These may be secured to ange 42 in any desired manner depending upon whether the flange material is of insulating or conducting material.

Movable contact arm 46 carries at the end thereof armature 50 consisting of a strip of soft iron. Armature 50 is normally disposed to overlap a portion of partition 41. Partition 41 adjacent armature Si) is provided with ferro-magnetic inserts 51 and 52, lying in suitable apertures in the partition so that the insert is accessible on both sides of cylindrical partition wall 41. The various -switch units are disposed at intervals on flange 43.

Carried by wall 42 is pin 55. Pin 55 may be rotatably secured 'in wall 42 or it may be a stationary pin. Carried by pin 55 is a permanent magnet assembly consisting of permanent magnet 56 and pole pieces 57 and 58. Pole pieces 57 and 5S are here illustrated as extending diametrically with respect to the axis of pin 55. Pole pieces 57 and 58 have pole faces at the ends thereof.

Assuming that the magnetic inserts in partition 41 are flush with the inside surface of the partition, pole pieces 57 and 58 may be so dimensioned as to snugly fit against the inside face of the partition. A suitable knob 60 on pin 55 may be used for turning the entire magnet assembly. If pin 55 is to be stationary then knob 60 will be coupled Ydirectly to engage the permanent magnet assembly so that the same may be rotated on `the pin to any desired position.

It is clear that the permanent magnet assembly may haveeach pole piece provided with a number of radial arms so that cach pole piece may be in the shape of a spider or each pole piece may only have one portion terminating in one pole face such as is illustrated in connection with Figs. 1 to 3 inclusive.

The annular region around the switch units may be enclosed by shroud 62. It is clear that the switch arrangement and supporting structure for the switches may be varied while retaining a cylindrical shape for the partition with the magnetic inserts.

A number of cylindrical units as illustrated in Figs. 4 and 5 may be arranged in tandem as illustrated in Figs. 6 and 7. There pin S5 is a shaft and is long enough to operate any `desired number of separate assemblies.

It is understood that both in Figs. 4 and 6 care will be exercised not to short circuit lpermanent magnet 56.

ceases This may be accomplished by having pin 55 andthe sleeve upon which the magnet assembly is secured made of non-magnetic material. lt is clear that in the construction illustrated in Figs. 4 to 7 inclusive, a hermetic seal between the two faces of the cylindrical partition may be obtained. It is also clear that the cylindrical construction may have the switch assemblies and control magnet assembly reversed so that the latter operates on the outside surface of the cylindrical partition.

Instead of using rigid material for the partition, it is possible to use flexible material and mold ferro-magnetic inserts at the proper regions. Some frame means for supporting the partition may be provided.

Referring now to Fig. 8, a pivoted construction is illustrated. Partition 70 has ferro-magnetic inserts 71 and 72. In addition a combined ferro-magnetic insert and pivot member 73 is provided. Member 73 has rounded head 74 on one side of partition 70 and portion 75 on the other side of partition 70. Resting on rounded head 74 is pole piece 77 attached to the bottorn pole face of permanent magnet 78. Attached to the top pole face of magnet 78 is a U-shaped pole structure 80 having side arms 81 and 82. Handle 83 is attached to pole structure 80 for rocking the magnet and pole structure as a unit from left to right, as seen in Fig. 8, and back again. The end pole faces of arms 81 and 82 are iinished to lie flush against the inserts. If desired, the insert faces may be slanted.

Rockable on part 75 is ferro-magnetic lever 85 having ends 85 and 87 with faces to cooperate with inserts 71 and 7'2. Pivot pin 88 may be provided to maintain armature 85 lagainst pivot part 75. It is clear that the position of armature 85 will be controlled by the magnet assembly. Armature 85 may control electric switches or other devices. The arrangement will provide snap action.

Partition 70 may have side walls 89 and cover 90 may be provided. Handle 83 may move in a slot in the cover. Thus a compact snap switch may be provided. Partition 70 may form part of an extensive wall for separating the regions on both sides of the partition.

Referring now to Fig. 9, a further modification is illustrated. Partition 92 has three ferro-magnetic inserts 93, 94, and 95. U-shaped permanent magnet 96 can bridge two adjacent inserts 93 and 94 or 94 and 95. The magnet or partition may be moved in a straight line to change from one pair of inserts to the other. Thus magnet 96 may be moved to the left. Cooperating with the inserts is a rocking lever arrangement consisting of levers 97 and 97a connected by spring 98. Levers 97 and 97a are of ferro-magnetic material and have one end of each bearing on middle insert 94. The free ends of the levers may cooperate with one or more switch contacts. The levers may be rocked from one position to another' by changing the relative position of magnet 96 and the inserts. Any other lever arrangement can be provided. Thus the rocking arrangement shown in Fig. 8 may be used. Levers 97 and 97a of Fig. 9 may be replaced by the rocking magnet assembly of Fig. 8 except that permanent magnet 78 of Fig. 8 would be replaced by a simple soft iron part. However, the magnet assembly may be used as in Fig. 8 with no change. In such case magnet 96 can be replaced by a simple piece of soft iron or magnet 96 may be used. Then either attraction or repulsion m-ay be utilized.

Under certain conditions, it may be desirable to have one or more ferro-magnetic inserts in a partition or wall which is quite thin, such as thin sheet aluminum, brass, plastic, or any other material. If the material is sufficiently thin, it may be desirable to have a ferro-magnetic piece cemented, soldered, or otherwise attached to one face of the partition rather than to make an insert. In such case, the thickness of the material itself making the wall or partition may be considered as negligible. In other cases, it may be preferred to have a thin layer of non-magnetic material in the magnetic circuitto` prevent sticking. It will, therefore, be understood that when the term ferro-magnetic insert is used that there is included a construction wherein the ferro-magnetic member may` have at least one face covered by a relatively thin layer of non-magnetic material which may or may not constitute part of the partition or wall.

Furthermore, there may be instances where two or more inserts may be merged into one large insert. As a rule, however, it is undesirable for an insert to have magnetic flux goin two directionsvin the-insert since the insert will then act as a magnetic short circuit. Fundamentally, the invention is concerned with having a control means or member on one'side of the partition and a load or part to be controlled upon the other side of the partition. Insofar as manual control is concerned, any one of the three components may be moved manually to obtain a control action. In general, the control movement will be applied to the control means while the load will be permitted to move itself in response to magnetic conditions. However, there is no reason why the partition cannot be moved.

What is claimed is:

l. A magnetically controlled apparatus adapted to have a control portion and a controlled portion hermetically isolated from each other by means of a partition, said partition comprising a rigid wall of non-magnetic material, said wall having one face for the controlled part and the other face for the control part, said wall having a plurality of discrete ferromagnetic inserts extending from one face of the wall through to the other face of the wall, said inserts having ends substantially ilush with the two wall surfaces and being substantially uniform in dimension from one end to the other end of the insert, controlled loads on the one side of said wall, said controlled loads including armatures normally biased away from the one face, each armature being disposed opposite an insert so that said armature may move toward said insert, control means on the other side of said wall, said control means including permanent magnet means providing at least one pole face for substantially matching the face of one ferromagnetic insert, means for mounting said control means for moving said pole face toward or away from a selected ferromagnetic insert, the control means cooperating with at least one selected insert and armature in selected positions to provide a substantially complete ferromagnetic circuit, the matcln'ng of a pole face and insert providing for eiiicient magnetic y operation at a selected position.

2. The construction according to claim l wherein said wall is at.

3. The construction according to claim 2 wherein said inserts are arranged in a circular pattern around a selected area of the wall and wherein the control means on the other side of said wall is movable over the face of said wall with said area as a center.

4. The construtcion according to claim 1 wherein said wall is cylindrical.

5. A snap-action control comprising a rigid non-magnetic partition wall having three ferromagnetic inserts, each insert extending through the partition wall from one wall face to the other wall face, said inserts being disposed along a straight line, armature means at one face of said wall, means for mounting said armature means for movement so that one armature portion is always in physical contact with the center insert, said armature means having other armature portions which on armature movement can contact one or other end inserts at any one time, permanent magnet control means on the other side of said wall, said permanent magnet control means including ferromagnetic portions for contacting the center insert and one or other end inserts depending upon the position-of said permanent magnet means and means for moving said permanent magnet means to select the position thereof whereby said armature means is correspondingly actuated and means controlled by said armature means.

6. The construction according to claim 5 wherein said armature means comprises an armature pivotally secured on said center insert and rockable to contact one or the other end insert.

7. The construction according to claim 5 wherein said permanent magnet means is slidable along the face of said partition and can simultaneously bear against a center insert and an end insert.

References Cited in the le of this patent UNITED STATES PATENTS 1,530,936 Greenwood Mar. 24, 1925 Whittaker Feb. 2, 1943 Harmon Apr. 17, 1945 Raettig Nov. 5, 1946 Hubbell Sept. 5, 1950 Grace Feb. 27, 1951 Kellett Nov. 13, 1956 Perkins et a1 I une 11, 1957 Mason Aug. 20, 1957 FOREIGN PATENTS Great Britain Apr. 23, 1931 Germany Mar. 12, 1931 

